Technical Field
Certain embodiment of the present invention relate to a cryocooler in which high-pressure refrigerant gas is expanded to generate coldness.
Description of Related Art
In the related art, as an example of a cryocooler which generates cryogenic temperatures, a Gifford-McMahon (GM) cryocooler is known. In the GM cryocooler, a displacer reciprocates in a cylinder, and thus, a volume in an expansion space is changed. The expansion space and a discharge side and a suction side of a compressor are selectively connected to each other according to the change of the volume, and thus, the refrigerant gas is expanded in the expansion space. A cooling object is cooled by the cold refrigerant gas.